Abstract:
In order to apply an electronic signature from a client station having authentication resources at a server, the following steps are carried out: the client station is authenticated at the server, thus establishing an authenticated communication channel; a private key/public key pair is generated at the client station; a signature certificate request generated by means of at least the public key is transmitted from the client station to the server via the authenticated channel; a signature certificate obtained in response to the request is returned via the authenticated channel; this certificate is verified at the client station; an electronic signature is calculated at the client station by means of the private key, after which this private key is destroyed; and the calculated signature is formatted with the aid of the signature certificate received via the authenticated channel.
Abstract:
To avoid recourse to a certification authority and to keep a trace of delegation to a delegate by a titleholder, a terminal of the titleholder draws up a second electronic certificate different from the normal certificate of the delegate. The second certificate includes at least a delegation attribute and a signature of the data in the second certificate by means of a private key of the titleholder. The titleholder behaves like a certification authority in respect of the second certificate, which is used for cryptographic actions by the delegate in the name of the titleholder.
Abstract:
A ring-signature scheme is adapted so that at least one of the variability parameter values used is an identity trace of the anonymous signatory, determined as a function of anonymity withdrawal data stored and held secret by an anonymity withdrawal entity in connection with an identification of the anonymous signatory. This provides a subsequent controlled capacity of withdrawing the anonymity of the signatory, either by an authority, or by the signatory himself.
Abstract:
A token of delegation from a first signatory to a second signatory is generated and the delegation token is associated with a document signed electronically by means of a cryptographic key of the second signatory. The delegation token contains delegation data signed electronically for the first signatory, in particular an identifier of the second signatory. It is generated by a server in response to a request relating to the signing of the document, sent by the second signatory.